CN114213179B

CN114213179B - Organic polymeric magnesium agent and preparation method thereof

Info

Publication number: CN114213179B
Application number: CN202111565203.1A
Authority: CN
Inventors: 石晓雨; 张鹰; 聂宏光; 张平; 张俊清
Original assignee: Liaoning Zhongke Biological Engineering Co ltd
Current assignee: Liaoning Zhongke Biological Engineering Co ltd
Priority date: 2021-12-20
Filing date: 2021-12-20
Publication date: 2022-12-02
Anticipated expiration: 2041-12-20
Also published as: CN114213179A

Abstract

The invention belongs to the field of chemical synthesis, and particularly relates to an organic polymeric magnesium agent for agricultural production and a preparation method thereof. Adding anhydrous magnesium sulfate into a stirring reaction kettle, slowly adding the high-molecular polyglutamic acid at the flow rate of 1L-10L/min under the stirring condition, keeping the reaction kettle at the constant speed of 40-70RPM, stirring, and reacting for 30-40 minutes to form white powdery solid, namely the organic polymeric magnesium agent. The organic polymeric magnesium agent takes polyglutamic acid fermentation liquor and anhydrous magnesium sulfate as raw materials, the raw materials are mixed and stirred according to a specific proportion, the dissolving heat of the anhydrous magnesium sulfate is utilized to promote magnesium ions and polyglutamic acid to form an organic polymeric state, meanwhile, a large amount of water in the fermentation liquor is evaporated, and a solid product of the organic polymeric magnesium can be directly obtained in a very short time.

Description

Organic polymeric magnesium agent and preparation method thereof

Technical Field

The invention belongs to the field of chemical synthesis, and particularly relates to an organic polymeric magnesium agent for agricultural production and a preparation method thereof.

Background

At present, the synthesis means of polyglutamic acid mainly depends on natural microbial fermentation, and other synthesis methods have few reports related to industrialization. Compared with other methods, the microbial fermentation method has the advantages of mild conditions, short period, high yield, proper molecular weight distribution and the like. The processes for synthesizing polyglutamic acid by biological bacteria fermentation mainly comprise two processes, namely liquid fermentation and solid fermentation, wherein the solid fermentation is recorded by scientific and technological articles early, but the process capable of being industrialized is only applied in recent years, and is rarely popularized in the market due to the problems of technical barriers.

The process widely applied to synthesis of polyglutamic acid is a liquid fermentation process, the main process of the process is to inoculate a kind of bacteria in a fermentation medium containing glutamic acid or glutamate, a carbon source, a nitrogen source, inorganic salt and water, carry out aerobic culture under proper conditions, the produced fermentation liquor has a certain content of polyglutamic acid, and then carry out specific treatment on the fermentation liquor according to different use fields, for example, in the field of cosmetics, the purity and content of the polyglutamic acid are higher, so that the operations of removing bacteria, pigments and impure proteins and purifying the fermentation liquor are needed, and the product can meet the use requirements of the cosmetic grade only after the processes of acidification, suction filtration, ultrafiltration concentration, alcohol precipitation, vacuum drying and the like.

In the field of agricultural application, the purity and content requirements of the polyglutamic acid are not high, so the production process has the main characteristics of simply, low-cost and quickly preparing the polyglutamic acid into a product, the polyglutamic acid fermentation liquor can be directly used in agricultural production and has a good effect, but the fermentation liquor contains a large amount of organic and inorganic nutrient substances, is extremely easy to decay and deteriorate when exposed in the air and is difficult to store, and the effect of the fermentation liquor is influenced by adding a preservative, so the fermentation liquor must be subjected to necessary treatment.

At present, most of processes for producing agricultural polyglutamic acid on the market are the cosmetic-grade processes, only the purification and impurity removal levels are simply reduced, various matched equipment is still needed in the processes, a large amount of high-risk chemical agents are needed for acidification and alcohol precipitation, the requirements on production environment are high, the whole process investment is large, and compared with the field of cosmetics, the added value of products in the field of agriculture is low, so that the processes are not suitable for production and preparation of the agricultural polyglutamic acid from the production cost perspective.

In addition, the fermentation liquor is processed into a solid form which can be stored for a long time by adopting adsorption and low-temperature drying modes in a part of processes, the polyglutamic acid fermentation liquor contains about 90 percent of water, and because the polyglutamic acid has certain viscosity, the adsorbent can be selected from a few types and is not water-soluble, so that the product is limited in agricultural application, in addition, the low-temperature drying energy consumption is huge, the time is long, and the production efficiency of the whole process is lower.

In conclusion, the polyglutamic acid fermentation liquid formed by natural fermentation of biological bacteria is difficult to store for a long time, and the solid product is processed by adopting an adsorption low-temperature drying mode, so that labor and time are wasted; the purification treatment cost is very high, and the industrial production is not easy to develop in the field of agricultural application. The above restriction conditions make large-area application of polyglutamic acid in agricultural production difficult.

Disclosure of Invention

The invention aims to provide an organic polymeric magnesium agent for agricultural production and a preparation method and application thereof.

In order to achieve the purpose, the invention adopts the technical scheme that:

a preparation method of an organic polymerization magnesium agent comprises the steps of adding anhydrous magnesium sulfate into a stirring reaction kettle, slowly adding high-molecular polyglutamic acid at a flow rate of 1L-10L/min under the stirring condition, keeping the reaction kettle at a constant speed of 40-70RPM, stirring, reacting for 30-40 minutes to form white powdery solid, and obtaining the organic polymerization magnesium agent.

50-60% of anhydrous magnesium sulfate and 40-50% of high molecular polyglutamic acid are mixed in the reaction kettle according to mass percentage.

And after the white powdery solid after the reaction passes through a 80-mesh sieve, crushing blocks remained on the sieve, and mixing the crushed blocks with undersize powder to obtain the organic polymeric magnesium agent.

The high-molecular polyglutamic acid is high-molecular polyglutamic acid fermentation liquor obtained by aerobic fermentation.

The content of the polyglutamic acid in the high-molecular polyglutamic acid fermentation liquor is 2-4%, and the molecular weight of the high-molecular polyglutamic acid fermentation liquor is distributed between 10 million and 200 million Dal.

The magnesium sulfate is anhydrous magnesium sulfate, the effective content of the magnesium sulfate is more than or equal to 98 percent, and the fineness is 80-100 meshes.

An organic polymeric magnesium agent, which is prepared by the method.

The application of the high-molecular polyglutamic acid in preparing the organic polymeric magnesium agent.

The high molecular polyglutamic acid is high molecular polyglutamic acid fermentation liquor obtained by aerobic fermentation.

The high molecular polyglutamic acid fermentation liquid is obtained by inoculating bacillus subtilis into a fermentation medium containing glutamic acid or glutamate and performing aerobic fermentation.

Namely, the above-mentioned high-molecular polyglutamic acid fermentation broth can be obtained by aerobic fermentation using existing Bacillus subtilis according to the prior art, for example, 1-in 2017, 44 (4): 1-in "journal of agriculture university, anhui" production of Gamma-polyglutamic acid by fermentation of Bacillus subtilis ".

The application of the organic polymeric magnesium agent, the application of the organic polymeric magnesium agent as a fertilizer synergist: applying root in 0.5-1 kg/mu amount; when the fertilizer is added into the fertilizer production, the addition amount of each ton of the fertilizer is 12.5-25kg.

The invention has the advantages that:

the organic polymerization magnesium agent takes polyglutamic acid fermentation liquor and anhydrous magnesium sulfate as raw materials, the raw materials are mixed and stirred according to a specific proportion, the dissolution heat of the anhydrous magnesium sulfate is utilized to promote magnesium ions and polyglutamic acid to form an organic polymerization state, simultaneously, a large amount of water in the fermentation liquor is evaporated, a solid product of the organic polymerization magnesium can be directly obtained in a very short time, the production process is simple, the energy is saved, the cost is low, and the organic polymerization magnesium agent is very suitable for industrial large-scale production. The preparation method solves the problem that the polyglutamic acid fermentation liquor is difficult to store and difficult to apply in agriculture, and can directly and quickly prepare the polyglutamic acid fermentation liquor into a solid form which can be stored for a long time. The obtained solid product has excellent water solubility, can be directly applied to the magnesium-deficient farmland, has high utilization rate of magnesium element, and can quickly supplement the magnesium element; the fertilizer can also be directly added into fertilizer products, and the fertilizer does not generate antagonistic reaction with phosphorus in the fertilizer, so that the activity of phosphorus and magnesium nutrients is effectively maintained, the rapid absorption and efficient utilization of the nutrients are promoted, and the dual purposes of magnesium supplement and nutrient synergy are realized.

Drawings

FIG. 1 is a graph of X-ray diffraction analysis (PXRD) of a structure of polymeric magnesium prepared by the present invention, wherein a: magnesium sulfate heptahydrate, b: anhydrous magnesium sulfate, c: the organic polymeric magnesium obtained by the embodiment of the invention.

FIG. 2 is a photograph of an organomolymagnesium product obtained by the preparation of the example of the present invention.

The specific implementation mode is as follows:

the following examples are presented to further illustrate embodiments of the present invention, and it should be understood that the embodiments described herein are for purposes of illustration and explanation only and are not intended to limit the invention.

The organic polymeric magnesium agent is an organic combination formed by reacting high-molecular polyglutamic acid with magnesium ions to obtain a solid product, solves the problem that the polyglutamic acid fermentation liquor is difficult to store and is difficult to apply in agriculture, can directly and quickly prepare the polyglutamic acid fermentation liquor into a solid form which can be stored for a long time, simultaneously removes a large amount of water in the fermentation liquor, saves the energy consumption of various drying operations in the prior preparation method, does not need to add suction filtration equipment for removing substances such as thalli, foreign proteins and the like in the process, simplifies the production steps, meets the application requirements in the field of agricultural production in the content of the polyglutamic acid in the obtained product, and is rich in a polymeric substance formed by combining the polyglutamic acid with magnesium.

The following examples were obtained for fermentation broth of polyglutamic acid:

(A process for preparing a polyglutamic acid fermentation broth is given here)

Preparing a seed culture medium according to the following mass percentages: 2% of glucose, 1% of sodium glutamate, 1% of magnesium sulfate, 1% of peptone, 0.2% of dipotassium phosphate and the balance of water, and adjusting the pH value to 7.0;

preparing a fermentation medium according to the following substances in percentage by mass: 5% of glucose, 0.04% of magnesium sulfate, 4% of sodium glutamate, 0.5% of ammonium sulfate, 3% of dipotassium phosphate, 0.2% of potassium dihydrogen phosphate, 0.005% of manganese sulfate and the balance of water, and the pH is adjusted to 7.0.

Seed culture was performed as follows: 50mL of seed culture medium is filled in a 250mL triangular flask, 100 mu L of bacillus subtilis strain is stored in an inoculation glycerin tube, the temperature is 30 ℃, the rotating speed is 220r/min, and shaking culture is carried out for 20 hours by a shaker to obtain the fermentation seed.

The fermentation culture is carried out according to the following method: inoculating the fermentation seed liquid into a fermentation culture medium according to the inoculation amount of 5%, wherein the liquid loading amount of a 250mL triangular flask is 50mL, the temperature is 30 ℃, and shaking culture is carried out for 48 hours in a shaking table at 220r/min, so as to obtain the polyglutamic acid fermentation liquid, wherein the content of the polyglutamic acid is more than or equal to 2.5%, and the molecular weight distribution of the polyglutamic acid is 70-100 ten thousand.

Example 1

Preparation of organic polymeric magnesium:

50kg of anhydrous magnesium sulfate with the purity of 99 percent is placed in a stirring reaction kettle, a stirring device of the reaction kettle is started to stir at a constant speed of 50RPM, then 40L of polyglutamic acid (with the molecular weight of about 100 ten thousand) fermentation liquor is slowly added at a flow dividing speed of 4L, then the mixture is placed at room temperature to react for 30 minutes, the stirring is continuously carried out in the process, a steam pumping device of the reaction kettle is started to drain steam generated by the reaction in time, after the reaction is finished, the materials poured out are sieved by a sieve of 80 meshes, the materials on the sieve are poured into a crusher to be crushed, and the crushed materials are mixed with the materials under the sieve to obtain white powdery polymeric magnesium (see figure 1 and figure 2).

The structural characteristics of the organic polymeric magnesium agent can be seen from FIG. 1 by X-ray diffraction analysis (PXRD): using p-Cu-Ka radiation on a D8Advance X-ray diffractometer

The crystals were subjected to a powder diffraction experiment. The glancing-off range is 5-45 deg., the step time is 0.3sec, the step length is 0.02 deg., and the collecting time is about 10min.

Respectively carrying out a reaction on magnesium sulfate heptahydrate and b: anhydrous magnesium sulfate, c: the magnesium was polymerized and subjected to powder X-ray diffraction testing under the conditions described above. As can be seen by comparing the powder diagrams, a: the main diffraction characteristic peaks of the heptahydrate and the magnesium sulfate are 14.90, 16.71,20.24,21.21,22.07,33.78 and 42.41; b: the main diffraction characteristic peaks of the anhydrous magnesium sulfate are 17.52,20.34,22.12,30.54 and 39.68; c: the main diffraction characteristic peaks of the polymeric magnesium are 18.89,24.59,25.20,28.99,33.92 and 36.56, and the main diffraction characteristic peaks of the polymeric magnesium and the main diffraction characteristic peaks of the anhydrous magnesium sulfate and the magnesium sulfate heptahydrate cannot be coincided as shown by dotted line positions in the figure, so that the novel product formed in the preparation method is a brand new substance combining the anhydrous magnesium sulfate and the magnesium sulfate heptahydrate, and no excessive anhydrous magnesium sulfate and magnesium sulfate exist in the polymeric magnesium.

Example 2

50kg of anhydrous magnesium sulfate with the purity of 98% is placed into a stirring reaction kettle, a reaction kettle stirring device is started, uniform stirring is carried out at 60RPM, 45L of polyglutamic acid (with the molecular weight of about 70 ten thousand) fermentation liquor is slowly added at the split flow rate of 5L, then the mixture is placed at room temperature for reaction for 30 minutes, stirring is carried out all the time in the process, a steam extraction device of the reaction kettle is started, water vapor generated in the reaction is timely discharged, after the reaction is finished, the material is poured out and passes through a 80-mesh sieve, the material on the sieve is poured into a crusher, and the crushed material is mixed with the material under the sieve, so that white powdery polymeric magnesium is obtained.

The resulting polymeric magnesium had the same characteristics and appearance as the material obtained in example 1.

The above embodiment shows that the mechano-polymerization magnesium agent of the invention is an organic combination formed by the reaction of high molecular polyglutamic acid and magnesium ions, the reaction is an exothermic reaction, and the proportion of materials, the liquid flow rate and the rotating speed of a reaction kettle in the reaction process have great influence on the formation of a final product, for example, improper control of the proportion of materials can cause the waste of magnesium sulfate or can not evaporate the water of all fermentation liquor; improper control of the liquid flow rate can cause uneven contact of the two materials and influence the formation of polymeric magnesium; the improper rotating speed of the reaction kettle can cause slow water loss, the blocky materials at the end of the reaction can increase and the like (namely, the mixing ratio of the polyglutamic acid and the anhydrous magnesium sulfate is more than 1, or the stirring rotating speed is less than 40RPM (too slow), the materials are not completely dried after the exothermic reaction is finished, the stirring rotating speed is more than 70RPM (too fast), or the inflow speed of the polyglutamic acid is more than 10L/min, and a large amount of hard materials are generated after the exothermic reaction is finished), and all the conditions can cause that the polymerized magnesium product cannot be effectively formed, so all indexes are strictly controlled in the process.

Test examples:

test subjects: in a cucumber greenhouse of large-depression town of ancient city, panjin, liaoning province, the experimental example obtained the influence of polymerized magnesium, common magnesium sulfate and chelated magnesium on the accumulation of chlorophyll in cucumber.

Test materials:

(1) Common fertilizer (Compound fertilizer 15-15-15)

(2) Magnesium sulfate heptahydrate (pure magnesium content 9.6%)

(3) Polymeric magnesium produced in example 2 (pure magnesium content 15%)

( 4) Comparative example chelated magnesium (pure magnesium content 2.5%, product name: characteristics of ethylene diamine tetraacetic acid disodium magnesium salt (EDTA-Mg-6): white powder, easily soluble in water, chelated magnesium not less than 5.8% )

And (3) experimental design:

the experiment sets 4 treatments (as shown in table 1), each treatment sets 3 levels, after cucumber field planting, the materials of treatment 1, treatment 2 and treatment 3 are applied at one time in a root irrigation mode along with water, the same amount of clear water is irrigated to roots in contrast treatment, and all factors are kept consistent except that the input materials are different in each treatment. Measuring and recording chlorophyll indexes of each treated cucumber leaf in two times 20 days and 35 days after the cucumber is transplanted, and finally taking the average value of each plant.

Table 1 test treatment

Test treatment
		Control	The root is irrigated by clear water with the same quantity of 40 kg/mu + of common fertilization and 1 and 2 treatments
Process 1	The root is irrigated with water by applying 40 kg/mu of common fertilizer and 1.56 kg/mu of magnesium sulfate heptahydrate
		Treatment 2	Common fertilizer application is 40kgExample 2 polymerization of magnesium 1 kg/mu with Water
Treatment 3	Irrigating roots with water for 40 kg/mu plus 6 kg/mu of chelated magnesium after common fertilization

Note: in the test, the pure magnesium input amount in the treatment 1, the treatment 2 and the treatment 3 is kept consistent and is 150 g/mu (667 m) ² )

TABLE 2 test results (chlorophyll SPAD)

Test treatment	20 days (Single plant average)	35 days (Single plant average)
			Control of	40.9	44.2
1	41.2	43.9
			2	50.9	52.2
3	44.1	45.1

The test results (as shown in table 2) show that: when the magnesium sulfate heptahydrate treatment (treatment 1) is applied to the control treatment, the difference between the green values of the leaves measured twice in 20 days and 35 days is not obvious, which is probably because the magnesium and phosphorus in the fertilizer have an ion antagonism effect, so that the magnesium input does not play a corresponding effect of promoting the accumulation of chlorophyll; when the polymeric magnesium treatment (treatment 2) and the comparative chelated magnesium treatment (treatment 3) are applied, compared with the control treatment and the treatment 1, the chlorophyll values measured twice are improved, which indicates that the polymeric or chelated magnesium has the characteristic of rapid absorption and accumulation, the magnesium ions are protected, the antagonism between the ions is avoided, the accumulation of chlorophyll in cucumber leaves is promoted, and the crop quality is improved. Whereas the polymeric magnesium treatment (treatment 2) is higher in value than the comparative chelated magnesium treatment (treatment 3). Therefore, the polymer magnesium obtained by the invention solves the problem of difficult agricultural application caused by difficult preservation of polyglutamic acid fermentation liquor, and meanwhile, the polymer magnesium obtained by the invention has higher effectiveness and better product performance compared with magnesium in common magnesium sulfate and chelated magnesium. When the polyglutamic acid is applied to agriculture, magnesium ions can be protected from being combined by other anions or being interfered by cations to lose nutrient activity, meanwhile, the polyglutamic acid can be directly absorbed by crops due to the self characteristics, and can be gradually decomposed into glutamic acid capable of being absorbed and utilized after carrying metal ions into the crops, so that the growth of the crops is continuously stimulated, and the quality of the crops is improved.

Claims

1. A preparation method of an organic polymeric magnesium agent is characterized by comprising the following steps: adding anhydrous magnesium sulfate into a stirring reaction kettle, slowly adding high-molecular polyglutamic acid at a flow rate of 1L-10L/min under the stirring condition, keeping the reaction kettle at a constant speed of 40-70RPM, and stirring to react for 30-40 minutes to form white powdery solid, namely the organic polymeric magnesium agent;

50-60% of anhydrous magnesium sulfate and 40-50% of high-molecular polyglutamic acid are mixed in the reaction kettle according to mass percentage;

the high-molecular polyglutamic acid is high-molecular polyglutamic acid fermentation liquor obtained by aerobic fermentation of bacillus;

the content of the polyglutamic acid in the high-molecular polyglutamic acid fermentation liquor is 2-4%, and the molecular weight of the high-molecular polyglutamic acid fermentation liquor is distributed between 10 million and 200 million Dals.

2. The method of preparing polymeric magnesium organyls according to claim 1, wherein: and after the white powdery solid after the reaction passes through a 80-mesh sieve, crushing blocks remained on the sieve, and mixing the crushed blocks with undersize powder to obtain the organic polymeric magnesium agent.

3. The method of preparing polymeric magnesium organyls according to claim 1, wherein: the magnesium sulfate is anhydrous magnesium sulfate, the effective content of the magnesium sulfate is more than or equal to 98 percent, and the fineness is 80-100 meshes.

4. An organic polymeric magnesium agent prepared by the method of claim 1, wherein: the organic polymeric magnesium agent prepared by the method of claim 1.